论文标题
$ cp $ yymmetries在稀有顶部衰减中$ t \ tocγ$和$ t \ to c g $
$CP$ asymmetries in the rare top decays $t\to cγ$ and $t\to c g$
论文作者
论文摘要
罕见的辐射风味变化的顶部衰减$ t \ tocγ$和$ t \ to cg $（以及少数$ t \ touγ$和$ t $ to $ t \ to ug $）几十年来一直是兴趣的过程，因为它们提供了研究顶级夸克属性的关键探针。然而，迄今为止，由这些循环水平过程产生的分支比率和$ CP $不对称的明确分析研究已引起了人们的注意。在这项工作中，我们提供了$ CP $不对称的配方，这是由于环路积分及其虚构部分的总体动力学贡献以及对预测标准模型（SM）分支分数的更新数值计算。这些罕见的过程被Glashow-iliopoulos-Maiani（GIM）机制抑制了SM。但是，此处介绍的结果很容易被导出，以在SM的最小扩展中使用，包括矢量样的夸克，或在两higgs-doublet模型中，在这些模型中，辐射性费米子衰变过程可以通过几个幅度来增强SM相对于SM增强。这样的过程为新的基本物理学提供了实验清洁的签名，并且可以通过当前的撞机实验来测试。这些主题超出SM理论是一种优雅的手段，可为来自风味物理，CKM和Precision Electroweak测量结果提供改进的全球拟合。
The rare radiative flavour changing top decays $t\to cγ$ and $t\to cg$ (and the even rarer $t\to uγ$ and $t\to ug$) have been processes of interest for decades as they offer a key probe for studying top quark properties. However an explicit analytical study of the branching ratios and $CP$ asymmetries resulting from these loop level processes has thus far evaded attention. In this work, we provide the formulation for the $CP$ asymmetry resulting from the total kinetic contribution of the loop integrals and their imaginary parts, as well as an updated numerical computation of the predicted Standard Model (SM) branching fractions. These rare processes are suppressed in the SM by the Glashow-Iliopoulos-Maiani (GIM) mechanism. However, the results presented here can easily be exported for use in minimal extensions of the SM including vector-like quarks or in Two-Higgs-Doublet models where radiative fermionic decay processes can be enhanced relative to the SM by several orders of magnitude. Such processes provide an experimentally clean signature for new fundamental physics and can potentially be tested by current collider experiments. These topical beyond the SM theories are an elegant means to provide improved global fits to the latest results emerging from flavour physics, CKM and precision electroweak measurements.
